The Metroliner III was departing Cooktown for Cairns. At about
250 ft above ground level the flight crew noticed that a fuel
by-pass light had illuminated. The crew reported that they then
retarded both engine power levers slightly in an attempt to
extinguish the light. The left engine torque indications
immediately began to fluctuate by about 5 percent but then
increased to 20 percent. The left exhaust gas temperature and fuel
flows were also fluctuating. The engine torque indications
continued to surge and the pilot-in-command elected to shut down
the engine as a precautionary measure. The crew then notified air
traffic control of their intention to return to the departure
runway, where the aircraft made a single engine landing.
Subsequent trouble shooting determined that the engine problem
was associated with a transient fault in the Single Red Line
computer for the left engine. The computer was replaced and the
aircraft was returned to service without recurrence.
The company safety officer reported that he conducted an
investigation into the incident and advised that, as the aircraft
performance was not significantly impaired and because there was no
indication of fire or catastrophic failure, it would have been more
appropriate for the crew to continue the climb with both engines
operating until a more detailed assessment of the situation could
be made.
The occurrence brief is based on information obtained from the
company's safety officer. The ATSB did not conduct an on-site
investigation into the occurrence.